Format: How important is knowing the format before purchase

[DNSB]

Originally Posted by dixieknits

I purchased a book today, using a discount code from Kobobooks and it did tell me it was an epub, drm free.. However, when I downloaded it, I got a zip file with about 60 numbers and letter instead of name of my book that was full of a bunch of html files????? What on earth is this...... and why did they tell me they were downloading an epub to me. I googled about it and am waiting for my son in law to come over and help me. Not a happy customer today, but usually I love Kobo and my Glo....

Either Kobo's website gibbled or your web browser had an issue. I've seen both when I've had a file download with odd names -- my quick test is to redownload the file with a different browser. However, epubs are a .zip file -- you can open them as an archive and take a look at the contents. I'd suggest renaming the file to whatever name you prefer (book_title - author_name.epub) and then opening it.

I've attached a screen shot of a .kepub (The Peshawar Lancers) opened in 7-Zip.

The specification for the epub file format has the following to say:

Open Container Format 2.0.1

An EPUB file is a group of files that conform to the OPS/OPF standards and are wrapped in a ZIP file.The OCF specifies how to organize these files in the ZIP, and defines two additional files that must be included.

The mimetype file must be a text document in ASCII that contains the string application/epub+zip. It must also be uncompressed, unencrypted, and the first file in the ZIP archive. This file provides a more reliable way for applications to identify the mimetype of the file than just the .epub extension.

Also, there must be a folder named META-INF, which contains the required file container.xml. This XML file points to the file defining the contents of the book. This is the OPF file, though additional alternative rootfile elements are allowed.

Apart from mimetype and META-INF/container.xml, the other files (OPF, NCX, XHTML, CSS and images files) are traditionally put in a directory named OEBPS.

Regards,
David

... they ask you what time it is and you tell them how to build a clock.

[dixieknits]

Thankyou, I renamed it xxxx.epub and it worked perfectly on my Glo. I dont' have another browser and honestly don't want something else to deal with. I'll try again tomorrow with another book I want that probably won't be drm free and see if they tell me ahead what it is.. Thanks for the help..ps. I thnk kepubs are the ones I do not like because they number the chapters not the book. Why on earth would they do that? Who cares how many pages one has completed in a chapter. I want to know where I am in the book..

[Nightyume]

Originally Posted by Lynx-lynx

You're quite right ... I should have noted that as it's the Kobo app that I use on the Playbook then it's def kepub only files.

However - on my playbook I use other apps to read epubs and PDFs; and the PDF app is excellent and using the playbook and that app really is the best way to view a PDF file.

For what it's worth the Kobo app (at least on Android) let's you import epub files (maybe other file types too but I can't remember).

[Nightyume]

Originally Posted by dixieknits

Thankyou, I renamed it xxxx.epub and it worked perfectly on my Glo. I dont' have another browser and honestly don't want something else to deal with. I'll try again tomorrow with another book I want that probably won't be drm free and see if they tell me ahead what it is.. Thanks for the help..ps. I thnk kepubs are the ones I do not like because they number the chapters not the book. Why on earth would they do that? Who cares how many pages one has completed in a chapter. I want to know where I am in the book..

Honestly, one reason for this is that it's less demanding. Since the device only has to worry about processing the data and rendering for a single chapter it reacts a lot faster (quite evident when doing things like changing font sizes). With epubs it basically treats the entire book as a single chapter making reaction times somewhat slower (but switching chapters is faster). Plus with kepubs you still get a xx% done, which refers to your progress in the whole book and not the chapter.

But this reminds me of one reason I sometimes might NEED an ADOBE drm epub. Adobe numbers the pages in a manner which is independent of device, OS, settings, fonts, formatting, etc. making it ideal for quoting/citing for anything official/academic (as long as your professors accept it).

[davidfor]

Originally Posted by Nightyume

Honestly, one reason for this is that it's less demanding. Since the device only has to worry about processing the data and rendering for a single chapter it reacts a lot faster (quite evident when doing things like changing font sizes). With epubs it basically treats the entire book as a single chapter making reaction times somewhat slower (but switching chapters is faster). Plus with kepubs you still get a xx% done, which refers to your progress in the whole book and not the chapter.

I don't think it does that. See https://wiki.mobileread.com/wiki/Adob...s#Page_numbers for how the page numbers are calculated. There is no need to render the complete book using that algorithm. From my experience, the time taken after changing the font settings is dependent on how big the chapter is, not the size of the book. And I don't see much difference between epubs and kepubs.

[Nightyume]

Originally Posted by davidfor

I don't think it does that. See https://wiki.mobileread.com/wiki/Adob...s#Page_numbers for how the page numbers are calculated. There is no need to render the complete book using that algorithm. From my experience, the time taken after changing the font settings is dependent on how big the chapter is, not the size of the book. And I don't see much difference between epubs and kepubs.

Well, if you use an adobe epub on a kobo device you'll notice that the page number does not automatically change every time you flip the page. This is because as you say it uses an algorithm to determine the page numbers. This means that as long as it's the same edition of the book the algorithm should calculate the pages at the same spots. It's nice that if I look at a screen of an adobe drm epub on my kobo i can g o to the same page number on the desktop and find the contents of the page to be the same.

As for the other thing I always found that changing pages, calling up the menu, rendering changes in font settings took ages longer on the glo with epubs than with kepus when dealing with large books, especially those anthologies containing multiple large novels in one epub/kepub.

[hwlester]

Originally Posted by Nightyume

Well, if you use an adobe epub on a kobo device you'll notice that the page number does not automatically change every time you flip the page. This is because as you say it uses an algorithm to determine the page numbers.

Yeah, this is one thing that annoys me about the Kobo app: it doesn't use absolute page numbers like my Sony reader does. I seem to remember that even sideloading an EPUB onto the Kobo app did the same thing, but I may be misremembering. Nice to hear that the Kobo devices do it correctly.

[DNSB]

Originally Posted by hwlester

Yeah, this is one thing that annoys me about the Kobo app: it doesn't use absolute page numbers like my Sony reader does. I seem to remember that even sideloading an EPUB onto the Kobo app did the same thing, but I may be misremembering. Nice to hear that the Kobo devices do it correctly.

The main issue with the Adobe page numbering algorithm is that it only works with identical ebooks. While it is independent of the display page size, it is sensitive to the compression and file structure of the epub file.

As I understand it, the algorithm looks at the compressed size of the file and counts 1 page per 1024 bytes of compressed data and always rounding up -- if you redo an epub file using a different compression algorithm, the page numbering can change. A 114 byte file or a 1024 byte file would show as 1 page while a 1025 byte file would show as 2 pages. You add up all those page counts and get the total number of pages in the ebook. Once you open a file, the pages within that file are evenly distributed over the uncompressed data size. A file that is 1025 bytes will be broken into two pages that are whose character count will depend on the uncompressed data size while a 2047 byte file would be broken into two pages which would be very likely to be much longer than those from the 1025 byte file.

There are other issues such as an attempt to compensate for the differences between a DRMed and non-DRMed file which may make page numbering differ between two otherwise identical files.

Adobe did offer a non-standard extension called page map which never seemed to get any traction. It worked by attaching page numbers to HTML anchor tags.

Regards,
David

[Nightyume]

Originally Posted by DNSB

The main issue with the Adobe page numbering algorithm is that it only works with identical ebooks. While it is independent of the display page size, it is sensitive to the compression and file structure of the epub file.

As I understand it, the algorithm looks at the compressed size of the file and counts 1 page per 1024 bytes of compressed data and always rounding up -- if you redo an epub file using a different compression algorithm, the page numbering can change. A 114 byte file or a 1024 byte file would show as 1 page while a 1025 byte file would show as 2 pages. You add up all those page counts and get the total number of pages in the ebook. Once you open a file, the pages within that file are evenly distributed over the uncompressed data size. A file that is 1025 bytes will be broken into two pages that are whose character count will depend on the uncompressed data size while a 2047 byte file would be broken into two pages which would be very likely to be much longer than those from the 1025 byte file.

There are other issues such as an attempt to compensate for the differences between a DRMed and non-DRMed file which may make page numbering differ between two otherwise identical files.

Adobe did offer a non-standard extension called page map which never seemed to get any traction. It worked by attaching page numbers to HTML anchor tags.

Regards,
David

It might not be perfect but at least it DOES offer a level of standardization, meaning of you include all the pertinent information (edition, distributor, place purchased) and not muck about with the settings or conversions, you should be able to safely use quotes and references

Originally Posted by hwlester

Yeah, this is one thing that annoys me about the Kobo app: it doesn't use absolute page numbers like my Sony reader does. I seem to remember that even sideloading an EPUB onto the Kobo app did the same thing, but I may be misremembering. Nice to hear that the Kobo devices do it correctly.

On the Glo there is (was?) an option in settings to show the page number in the margin so you'd know when the new page started exactly. I don't know if it's limited to Adobe drm epubs or if it will work with others.

[DNSB]

Originally Posted by Nightyume

On the Glo there is (was?) an option in settings to show the page number in the margin so you'd know when the new page started exactly. I don't know if it's limited to Adobe drm epubs or if it will work with others.

The page number display works with any epubs.

On a slightly different note, it appears that the Kobo forum tradition of topic drift is still alive and well.

Regards,
David

[PeterT]

Originally Posted by DNSB

The page number display works with any epubs.

On a slightly different note, it appears that the Kobo forum tradition of topic drift is still alive and well.

Regards,
David

How about those Canucks?

[DNSB]

Originally Posted by PeterT

How about those Canucks?

At this point, I'm paying more attention to the Lions.

I do chant "pre-season" every few minutes but at this time, I think the Canucks will/have run into the same issue most teams do. You've been successful and now you have an aging team and will need to start looking at getting younger.

Somewhat more on topic, FW 2.90 does interesting things to an Aura HD.

What can I say?

I can resist anything except temptation.― Oscar Wilde, Lady Windermere's Fan

Regards,
David

[hwlester]

Originally Posted by DNSB

The main issue with the Adobe page numbering algorithm is that it only works with identical ebooks. While it is independent of the display page size, it is sensitive to the compression and file structure of the epub file.

Quite interesting. The main thing I like about it is a general idea of how far through the book you are. My wife's Nook 1st gen shows a progress bar at the bottom and the Sony will show something like "Page 115 of 512".

Originally Posted by Nightyume

On the Glo there is (was?) an option in settings to show the page number in the margin so you'd know when the new page started exactly. I don't know if it's limited to Adobe drm epubs or if it will work with others.

My old Sony PRS-600 had that and you couldn't disable it. It would sometimes overlay the text of the book if the margins were too tight. They removed it on the PRS-T1 and I don't think you can enable it. As David mentioned, the desktop version of ADE offers this as well. I actually prefer it off.

[witchkitten]

I know it's off topic, but I hate static page numbers. I much prefer dynamic ones because that gives me more of an idea about how long the chapter and book actually is (especially when comparing one book to another with the same font/margins etc.) and it makes me feel better to see the page numbers progressing even if there are more of them. Even when I read books with others I still think the page numbers are problematic because the page numbers change when DRM is removed or with slight changes to the book. Not to mention that most of my friends are still reading paper copies. When I read along with people I usually just reference the chapter. As for quoting, I don't think page numbers are necessary in an ebook because one can just search for the quote and find it easily. According to MLA, when citing an ebook in text only the chapter is referenced. They specifically say not to use page numbers because they change depending on the ereader.

I didn't realize Kobo uses static page numbers when epubs are side loaded (I've only seen non-side loaded examples). That makes me less inclined to replace my Nook with a Kobo, though I'm still thinking about it for other reasons. It seems there are no e-ink readers that use dynamic page numbers . I really miss Stanza, which I used on my iPhone for ereading before I got a Nook. I'll never forgive Amazon for killing it.

[samhy]

@witchkitten There is a Calibre plugin that creates a kepub file before sending it to a Kobo device. It works fine up until firmware 2.8.2. There are some changes with firmware 2.9.0 regarding the stats, but I'm not sure what becomes of the screen number per chapter and time left.